Michail Mamakos, "Overlapping coalition formation under uncertainty", Master Thesis, School of Electrical and Computer Engineering, Technical University of Crete, Chania, Greece, 2017
https://doi.org/10.26233/heallink.tuc.67719
Research in cooperative games often assumes that agents have complete information regarding the coalitional values, and that they can belong to one coalition only. In this thesis, we remove these unrealistic restrictions, and study various aspects of uncertainty facing agents in coalition formation environments, while allowing them to belong to multiple coalitions simultaneously.We begin by focusing on agent uncertainty regarding the resource contributions of potential partners. To tackle this, we provide three novel methods that obtain probability bounds for assessing the success of teams towards coalitional task completion. Our first method is based on an improvement of the Paley-Zygmund inequality, while the second and the third are devised based on the two-sided Chebyshev’s inequality and the Hoeffding’s inequality, respectively. Our methods allow agents to demand certain confidence levels regarding the resource contribution of coalitions; and agent beliefs are updated in a Bayesian manner, following formation decisions.We then proceed to study situations where agent uncertainty is over the underlying collaboration structure, which determines the values of the (possibly overlapping) coalitions. In this context, we first propose a novel concise representation scheme, termed ”Relational Rules“, which extends the celebrated MC-nets representation to cooperative games with overlapping coalitions. We then present a novel decision-making method for decentralized overlapping coalition formation, which employs, for the first time in the coalition formation literature, “Probabilistic Topic Modeling” (a highly successful unsupervised learning approach). We demonstrate experimentally that by interpreting formed coalitions as documents, agents using our approach are able to effectively and efficiently learn profitable collaboration patterns (or “topics”).